1. Field of Invention
This invention relates to fluid ejection systems having fluid ejection heads and replaceable fluid supply cartridges.
2. Description of Related Art
Fluid ejection systems, such as, for example, ink jet fluid printers and plotters, have a fluid ejection head with a fluid supply, either integral with the fluid ejection head, or connected to the fluid ejection head. A fluid ejection head contains a plurality of fluid channels that carry fluid from the fluid supply, such as, for example, a fluid supply cartridge, to respective fluid ejecting nozzles. A maintenance/capping station is often provided in such fluid ejection systems. At the end of an ejection operation, the fluid supply cartridge and fluid ejection head face are placed opposite the maintenance/capping station. The maintenance/capping station includes a capping chamber and an associated suction pump communicating through a waste tank and conduit lines. The capping chamber is movable into and away from the fluid ejection head. The capping chamber is used to prime the fluid ejection head with fluid when connected to the fluid ejection head and suction is applied to draw fluid through the fluid ejection head openings, as well as to remove dried fluid, contaminants and gas bubbles from the fluid ejection head.
Fluid ejection systems, such as ink jet printers and plotters, typically use four different color fluids, such as, for example, the three subtractive primary colors of cyan, yellow and magenta, and the achromatic color black. Ink jet printers and plotters may use different numbers of ink supply cartridges, such as, for example, four separate ink supply cartridges or two ink fluid supply cartridges, one having three compartments for the primary color inks, and the other ink tank having black ink. Alternatively, one tank with four compartments may be provided for the four different color inks.
If the user of a fluid ejection system, such as an ink jet printer or plotter, changes an ink color or type of ink being used in the fluid ejection system, such as, for example, a change from certain subtractive primary inks to pantone color or photographic color inks, if the new ink is incompatible with the old ink, the quality of the printed product or printed image will be decreased, often to the point of being unfit for its intended use. One way to avoid ink incompatibility problems is to insure that new inks are backward compatible with older inks or different types of ink. Unfortunately, this is not always possible.
U.S. Pat. No. 5,634,170 to Knapp et al. discloses a method and apparatus for filtering and sensing a developer fluid in a printing or copying machine to ensure that developer fluid reclaimed from a developing process is free from contamination. In col. 7, lines 34-45, Knapp et al. teaches an advantage of having a filtering station when the color of toner at a developing station is changed to another color of toner, for example, when a specialty of custom color toner has been used in a developer housing and is replaced with another color toner. Knapp et al. points out that it is very important that the reclaimed fluid be free of the first color of toner so that the second color of toner is not contaminated with the first color of toner, especially when a dark colored toner is replaced with a light color toner. Knapp et. al also teaches a toner sump cleaning mode in col. 12, lines 5-17, where cleaned reclaimed fluid is circulated through the filtering/sensing process until the fluid in the toner sump is free from toner. Then another color toner can be added to the toner concentration holding station. Knapp et al. also teaches having cleaned fluid travel to the diluent holding station rather than to the toner sump when desired.
This invention provides systems and methods that allow incompatible fluids to be used in a fluid ejection system.
This invention separately provides systems and methods for flushing a fluid ejection head connected to a removable fluid supply tank.
This invention further provides systems and methods that flush a fluid ejection head using a fluid supply tank containing a flushing fluid.
This invention also provides systems and methods that flush a fluid ejector head using at least two distinct fluids contained in at least two fluid supply tanks that are separately used to flush the fluid ejector head.
This invention also conditions the fluid injector head and a maintenance/capping station of a fluid ejection system to fluids distinct from existing and/or previously used fluids.
The systems and methods according to this invention provide a simple, easy-to-use cleaning technique for fluid ejection systems, including ink jet printers, which does not involve a separate toner concentration holding station, a diluent holding station with separate diluent supply lines, a toner sump, or elaborate sensing equipment.
The systems and methods according to this invention modify known fluid supply cartridges by filling one or more of such fluid supply tanks with one or more of a flushing fluid an ejection-fluid ink miscible fluid, such that the fluid supply tanks become flush tanks. Depending on the composition of the original ejection fluid relative to the composition of the new or replacement ejection fluid, more than one flush fluid may be required to achieve an effective flushing of the old fluid from the fluid ejection system. In various exemplary embodiments, in situations where more than one flush fluid is required, one flush fluid may be used to flush the original ejection fluid from the fluid ejection head and/or the maintenance/cap mechanism of the fluid ejection system. The second flush fluid is then used to condition the fluid ejection head and/or the maintenance/capping station for the new ejection fluid.
In various exemplary embodiments, the fluid ejection systems and methods according to this invention employ a fluid ejection head that accommodates different ejection fluid supply tanks. In this case, a flush tank is loaded into the fluid ejection head in the same manner as the standard ejection fluid supply tanks. When the fluid ejection system is an ink jet printer, for example, the flush tank contains a colorless, or slightly tinted, fluid so that the flush tank can be distinguished from an ink supply tank. The flush tank cleaning and conditioning fluids are used to clean the fluid ejection head and/or the capping/maintenance station components. The waste tank portion of the capping/maintenance station is used to collect all fluids ejected into the maintenance/capping station, whether one or more fluid ejection heads are used. The fluid receiving caps and the fluid lines to the waste tank portion of the capping/maintenance station can also be cleaned using the flush fluids
These and other features of the invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.